A207372 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 1 vertically

20, 400, 1260, 7130, 31110, 95220, 353808, 1047717, 3056647, 8773795, 23208895, 61308120, 155644140, 385081690, 938448639, 2231352160, 5231232640, 12073401891, 27463516024, 61756669106, 137220631975, 301814503696

Offset

1,1

Comments

Row 7 of A207368

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 7*a(n-1) -11*a(n-2) -19*a(n-3) +24*a(n-4) +148*a(n-5) -154*a(n-6) -372*a(n-7) +64*a(n-8) +1196*a(n-9) +12*a(n-10) -1502*a(n-11) -1463*a(n-12) +1885*a(n-13) +1364*a(n-14) +844*a(n-15) -1509*a(n-16) -469*a(n-17) -3160*a(n-18) +1214*a(n-19) +1531*a(n-20) +3827*a(n-21) -2031*a(n-22) +283*a(n-23) -3360*a(n-24) +392*a(n-25) -1491*a(n-26) +3515*a(n-27) -479*a(n-28) +1537*a(n-29) -1768*a(n-30) +618*a(n-31) -1700*a(n-32) +920*a(n-33) -429*a(n-34) +847*a(n-35) -416*a(n-36) +424*a(n-37) -379*a(n-38) +133*a(n-39) -165*a(n-40) +119*a(n-41) -67*a(n-42) +59*a(n-43) -23*a(n-44) +13*a(n-45) -11*a(n-46) +5*a(n-47) -3*a(n-48) +a(n-49)

Example

Some solutions for n=4
..1..0..0..1....1..0..1..0....0..1..0..1....0..1..0..1....0..1..0..0
..0..1..0..0....0..0..1..0....1..0..1..0....1..1..1..1....0..0..1..0
..1..0..0..1....1..0..1..0....0..1..0..1....0..1..0..1....0..1..0..0
..0..1..0..0....0..0..1..0....0..0..1..0....1..0..0..1....0..0..1..0
..1..0..0..1....1..0..1..0....0..1..0..1....0..1..0..0....0..1..0..0
..0..1..0..0....0..0..1..0....0..0..1..0....1..0..0..1....0..0..1..0
..1..0..0..1....1..0..1..0....0..1..0..0....0..1..0..0....0..1..0..0

Crossrefs

Sequence in context: A075843 A208072 A208122 * A208017 A208559 A209080

Adjacent sequences: A207369 A207370 A207371 * A207373 A207374 A207375

Keyword

nonn

Author

R. H. Hardin Feb 17 2012

Status

approved